Aroma diffuser



FIG. 1 is a front view of the aroma diffuser showing my new design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a side view thereof; and,

FIG. 5 is a perspective view thereof. 

I claim the ornamental design for an aroma diffuser, as shown and described. 